; (function flexible(window, document) {
  var docEl = document.documentElement
  var dpr = window.devicePixelRatio || 1

  // adjust body font size
  // function setBodyFontSize() {
  //   if (document.body) {
  //     // document.body.style.fontSize = 12 * dpr + 'px'
  //   } else {
  //     // document.addEventListener('DOMContentLoaded', setBodyFontSize)
  //   }
  // }
  // setBodyFontSize()

  // set 1rem = viewWidth / 24
  function setRemUnit() {
    var rem = docEl.clientWidth / 24
    docEl.style.fontSize = rem + 'px'
  }

  setRemUnit()

  // reset rem unit on page resize
  window.addEventListener('resize', setRemUnit)
  window.addEventListener('pageshow', function (e) {
    if (e.persisted) {
      setRemUnit()
    }
  })

  // detect 0.5px supports
  if (dpr >= 2) {
    var fakeBody = document.createElement('body')
    var testElement = document.createElement('div')
    testElement.style.border = '.5px solid transparent'
    fakeBody.appendChild(testElement)
    docEl.appendChild(fakeBody)
    if (testElement.offsetHeight === 1) {
      docEl.classList.add('hairlines')
    }
    docEl.removeChild(fakeBody)
  }
})(window, document)
